View Full Version : help me buy an er20 collet for my lathe/mill

12-11-2014, 09:57 PM
Hi All

Hope you can spare the time to help me

I have a chester MF42B lathe/mill

I wish to buy an er20 collet holder for my mill. Im very unexperienced in this area and therefore would like your help and advice in what one to buy

I have removed the taper.. from the headstock (picture attached)

dimensions are as follows

A 20.1
B 24.5
C 83

D 15.8
E 14.7
F 30

the thread that bolts into it, is 11.8mm and seems to accept a m12 thread

ive read about morse tapers, and am assuming its a #3 morse taper

so, do I buy one of these?


i really dont know what im doing... so any advice would be greatly appreciated.



12-11-2014, 10:19 PM
If it is the headstock you are talking about I would have thought an ER20 chuck with a straight shank held in the 3 jaw chuck would be easier and more convenient

12-11-2014, 10:22 PM
wrong terminology on my behalf. Its got nothing to do with the headstock. I meant, I pulled the taper out of the mill head :worked_till_5am:

12-11-2014, 10:26 PM

12-11-2014, 10:52 PM
Certainly looks like morse taper, and the dimensions you give suggest MT3. So the collet chuck you pointed to should work OK, especially as it also is M12 for the drawbar. You might be looking for ER20 because you already use that collet size somewhere else so you have a range of collets, but ArcEuroTrade sell ER25 collet chucks on an MT3 shank. However, I suspect that ER20 will hold as big a cutter as you would want to use on that machine - it will take a 1/2" shank cutter; ER25 goes to 16mm/5/8". Main advantage of ER25 is that you can also get a ball-bearing collet closing nut which makes it a bit easier to get a good grip on tools but in this size, it probably doesn't make a lot of difference.

I've been happy with various things I've bought from RDG in the past, although Arc Euro aren't bad either.

13-11-2014, 02:03 AM
ive also brought from RDG, and had good service, but i got my collect chuck kit from chronos (http://www.chronos.ltd.uk), while i was there collection a rotary table a while back.
worth a look to see what deals they have on.